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Abstract: The paper reports the results of an experimental investigation aimed at evaluating the role of hydrodynamic conditions on properties (physical, chemical and biochemical) of granular biomass grown under aerobic conditions in a SBBR (i.e. sequencing batch biofilter reactor). The granular biomass was characterised by a high density (i.e. 70–110gVSS/Lbiomass) that permitted to achieve a biomass concentration such high as 20–38gVSS/Lbed. The biomass density increased quasi-linearly with the increase of shear forces. The extracellular polymeric substances (EPS) content was rather low (5–6% of the total organic matter) and mostly made up of proteins whereas the cellular protein content, a parameter frequently used as an indicator of microorganisms activity, was high (30–60% of total organic matter). In addition, the EPS content and composition were not affected by hydrodynamic shear forces as well as the biomass hydrophobicity and protein content that, however, both seem to be affected by starvation. [Copyright &y& Elsevier]

Abstract: Acrylic acid (AA) and acrylonitrile (AN) were graft polymerized onto cellulose fluff pulp using ceric ammonium nitrate as initiator. The resulting copolymers were saponified with dilute sodium hydroxide and characterized by FT-IR, SEM and TGA. The potential value of the modified cellulose was assessed through measurements of absorbency properties. A fibre-hydrogel was prepared by an addition of a bifunctional monomer, ethyleneglycol dimethacrylate (EDMA) used for grafting. In second approach, biocide cellulose carbamate was prepared by impregnating the fibres in aqueous thiourea solution and subsequent grafting with acrylonitrile. Antimicrobial activity of the treated cellulose sample was studied against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis according to AATCC test method 100–1999. The results show that the treated fibre gives higher antimicrobial activity. The strong antimicrobial functions achieved on modified fibres, proved that the synthesized biomaterial was effective, very simple and practical to the textile finishing industry. [Copyright &y& Elsevier]